IIRC, a Hobie 20 only has 8:1 downhaul (per class rules), which may be too little to effectively de-power the main. Going from 8:1 to 16:1 on my Nacra 5.8 made a world of difference. It's a much more delicate adjustment then feathering or dumping mainsheet. It also gives the crew something to play with on the upwind leg.